1. Field of the Invention
The present invention relates to a tape carrier for TAB (hereinafter referred to as TAB tape carrier) and particularly to a TAB tape carrier for mounting electronic parts by a TAB method.
2. Related Art
A TAB tape carrier is widely used for mounting electronic parts such as semiconductor devices by a TAB (Tape Automated Bonding) method.

A demand for reduction in weight, thickness and size of such a TAB tape carrier has been increasing with the advance of the demand for reduction in weight, thickness and size of electronic parts in recent years.
On the other hand, such a TAB tape carrier is generally carried in the condition that sprockets are engaged with feeding holes formed along a lengthwise direction of the TAB tape carrier at opposite end portions in a widthwise direction of the TAB tape carrier so that a predetermined amount of tension is applied to the TAB tape carrier. For this reason, if the TAB tape carrier is formed so as to be too thin, the feeding holes may be broken at the time of carrying the TAB tape carrier or the positions of the feeding holes may be displaced at the time of mounting and bonding electronic parts.
Therefore, for example, JP-A-5-29394, JP-A-2000-332062, and JP-A-2000-340617 have proposed the provision of a sheet of copper foil on a rear surface of an electrically insulating film to reinforce the electrically insulating film in the condition that electric conductor patterns are formed on a front surface of the electrically insulating film.
The demand for reduction in weight, thickness and size and the demand for reduction in size and density of the electric conductor patterns have been increasing in recent years. These demands cannot be satisfied sufficiently by the reinforcing effect of copper foil. To satisfy these demands, greater improvement in dimensional accuracy and positional accuracy has been required at the time of carrying the TAB tape carrier or at the time of mounting and bonding electronic parts.